Oilseed Crops in Western Canada Alfalfa Looper Aphids

Oilseed Crops

Western Committee on Crop Pests Guide to Integrated Control of Insect Pests of Crops

Insect Management In Oilseed Crops in Western Canada (Canola, mustard, flax, sunflowers, safflower)

John Gavloski; Manitoba Agriculture and Resource Development

Last Updated: August 2021

Note: For pesticide toxicity to bees see the chapter in this guide on: "Hazards and Safeguards in Applying Insecticides to Crops in Bloom"; the link for this reads “Bee Poisoning”.

Alfalfa Looper Autographa californica (Speyer) (Lepidoptera: Noctuidae)

Alfalfa Looper (canola)

Economic threshold - No thresholds have been determined for the alfalfa looper in canola but check threshold levels for the Bertha armyworm as a guideline.

Chemical Control – IPM status of insecticides – All the insecticides registered in Canada for alfalfa looper in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Insecticide Rate Rate Preharvest (vol/acre) (vol/ha) Interval (days) References Chlorpyrifos1 Lorsban/ Pyrinex 0.3 - 0.4 L 0.75-1.0 L 21 1-3 /Nufos /Citadel /Warhawk

References - 1. Dolinski et al., Pest. Res. Rep. 1973:136. 2. Jacobson et al., Pest. Res. Rep. 1973:137. 3. McDonald, Pest. Res. Rep. 1973:252.

1Registration of chlorpyrifos has been cancelled. Existing stocks in Canada are being phased-out. The last date of sale by retailers is December 10, 2022. All use of chlorpyrifos must cease by December 10, 2023.

Aphids (Hemiptera: Aphididae)

Main species of aphids on crop: Flax: Potato aphid, Macrosiphum euphorbiae (Thos.) (Hemiptera: Aphididae) Canola: Turnip aphid, Lipaphis erysimi (Kltb.) (Hemiptera: Aphididae) 1

WCCP Guide to Integrated Control of Insect Pests o f Crops

Monitoring- Flax - Flax should be sampled for aphids when the crop is in full bloom, and assessed again at the green boll stage if aphid densities are near the threshold but not controlled (3). Sample 25 plants at full bloom or 20 plants at early green boll growth stage (4). Sequential sampling plans are available for aphids in flax (4). Potato aphids are easily dislodged from flax by tapping a plant against a hard surface such as a tray (4). Potato aphids emigrate from flax in mid-August. Farmers need not sample or control the potato aphid in flax after mid-August (5).

Economic Threshold - Flax – The economic threshold for the potato aphid in flax is 3 aphids per plant at full bloom and 8 aphids per plant at the green boll stage (3). The yield loss of flax is 0.021 t/ha per aphid per plant for crops sampled at full bloom and 0.008 t/ha per aphid per plant for crops sampled at the green boll stage (3). Potato aphids can cause yield losses of 20% or more in flax when it reaches densities of 50 or more aphids per plant, but reduce the weight of individual seeds only slightly and has no effect on oil quality (3).

Canola - As a nominal threshold, control may be justified when at least 10-20% of the stems are infested with a cluster of aphids in flowering to early pod stages.

Chemical Control - Apply to canola only if aphids are found in clusters on the shoot tips.

IPM status of insecticides – All the insecticides registered in Canada for aphids in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Insecticide Crop Rate Rate Preharvest (ml/acre) (ml/ha) Interval (days) References Dimethoate Lagon /Cygon Canola 344-364 850-900 21 2 Flax 177 437

References - 2. Wise, Pest Mgmt. Res. Rep. 1991: 48, 49. 3. Wise et al. 1995. Can Entomol. 213-224. 4. Wise and Lamb. 1995. Can. Entomol. 967-976. 5. Lamb et al. 1997. Can. Entomol. 1049-1058.

Aster Leafhopper Macrosteles quadrilineatus Fbs. (Hemiptera: Cicadellidae)

The aster leafhopper is the main vector of the phytoplasma that causes aster yellows, which can infect many crops including canola, flax and sunflowers.

Symptoms of aster yellows in canola generally include stunting, virescence (the abnormal development of

Oilseed Crops green pigmentation in plant parts that are not normally green), leaf yellowing or purpling, phyllody (the abnormal development of floral parts into leafy structures), and formation of bladder-like siliques (1).

Chemical Control –

IPM status of insecticides – All the insecticides registered in Canada for aster leafhopper in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Insecticide Crop Rate Rate Preharvest (ml/acre) (ml/ha) Interval References (days)

Dimethoate Lagon /Cygon Canola 344 –364 850-900 21

References - 1. Olivier et al. 2006. Plant Disease. 6: 832

Banded Sunflower Moth – see section on Sunflower Moths

Beet Webworm Loxostege sticticalis (Linnaeus) (Lepidoptera: Crambidae)

Beet webworm (canola, mustard and flax)

Economic threshold - No thresholds have been determined.

Chemical Control – IPM status of insecticides – All the insecticides registered in Canada for beet webworm in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Insecticide Crop Rate Rate Preharvest (vol/acre) (vol/ha) Interval References (days)

Deltamethrin Canola, 7 1 Decis 5 EC Mustard, Flax 40 - 60 ml 100-150 ml 40 (Poleci in Decis 100 EC 20-30 ml 49-74 ml flax) Poleci 81 – 121 ml 200-300 ml

References - 1. Harris, Pest. Mgmt. Res. Rep. 1990:36. 3

WCCP Guide to Integrated Control of Insect Pests o f Crops

Bertha Armyworm Mamestra configurata Walker (Lepidoptera: Noctuidae)

Bertha Armyworm (canola, mustard and flax)

Monitoring - Larvae- Monitor for larvae when plants are in the early pod stage (stages 5.1-5.2). Count the number of larvae in a 0.25m2 area in 10 to 15 different locations in the field (1). A 3-sided frame can be used to define the area to be sampled. Plants within each sampling unit should be shaken by hand, then the soil surface examined for larvae and earthen lumps and plant debris moved to expose hidden larvae (2). Bertha armyworm larvae were found to have a moderately clumped distribution in canola (1), thus samples should be from different areas of the field. Adults- Adult male moths can be monitored during June and July using pheromone-baited traps. These traps can determine the presence of adults, but do not predict larval levels in a particular field (3). Development rates: Day-degrees for the development of various stages of bertha armyworm have been determined (23). With a development threshold of 7°C, 82, 356, and 352 accumulated day-degrees above the threshold are required for development of eggs, larvae, and pupae, respectively.

Economic Thresholds - A loss in canola of 0.058 Bu/acre for each larvae/m2 can be expected (4). From this, the following table of economic injury levels for bertha armyworm in canola has been calculated:

Economic Injury Levels For Bertha Armyworm In Canola Insecticide Expected seed value - $/bushel Application 6 7 8 9 10 11 12 13 14 15 16 Cost - $/ac # Larvae/metre2 7 20 17 15 13 12 11 10 9 9 8 8 8 23 20 17 15 14 13 11 11 10 9 9 9 26 22 19 17 16 14 13 12 11 10 10 10 29 25 22 19 17 16 14 13 12 11 11 11 32 27 24 21 19 17 16 15 14 13 12 12 34 30 26 23 21 19 17 16 15 14 13 13 37 32 28 25 22 20 19 17 16 15 14 14 40 35 31 27 24 22 20 19 17 16 15 15 43 37 32 29 26 23 22 20 19 17 16

Thresholds apply to both Argentine and Polish type canola and not to mustards, which are higher because they are a less preferred host (5) and have a greater ability to compensate for feeding damage (6).

Drought stress on canola may result in early dropping of leaves. Lack of leaves may cause more pod feeding by the larvae and affect yield more directly. Also, canola may not compensate as well for tissue loss under stressed conditions. Thus, under moisture stress, economic thresholds for bertha armyworm may be lower than indicated in the above table. Under severe drought stress, dividing the economic thresholds above by 1.48 may give more appropriate economic thresholds (4).

Cultural control - Fall tillage may increase the overwintering mortality of bertha armyworm pupae (7).

Oilseed Crops

Biological Control- Parasitism by the ichneumon wasp Banchus flavescens may exceeds 40%, and a tachinid fly, Athrycia cineria, may kill over 20% of bertha armyworm (8).

Pathogens isolated from bertha armyworm larvae include the fungus Entomophthora sp., and a nuclear polyhedrosis virus (9). Infection by the nuclear polyhedrosis virus in more than 95% of the bertha armyworm population have been recorded (10).

Chemical Control – IPM status of insecticides – Chlorantraniliprole is not harmful to some beneficial insects, such as parasitic Hymenoptera (24). All the other insecticides registered for bertha armyworm in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Insecticide Crop Rate Rate Preharvest (vol/acre) (vol/ha) Interval References (days) Chlorantraniliprole Canola, Coragen mustard, 51 – 152 ml 125 – 375 ml 1 flax Deltamethrin Canola, Decis 5 EC mustard, 40 - 60 ml 100-150 ml 7 11-16 Decis 100 EC flax 20-30 ml 49-74 ml Poleci (canola and 81-121 ml 200-300 ml mustard only) Cypermethrin Mako Canola 28 ml (ground) 70 ml (ground) 36 ml (air) 90 ml (air) 30 -

UP-Cyde /Ship 81-113 ml 200-280 ml Lambda-cyhalothrin Canola, - Matador /Silencer mustard 34 ml 83 ml 7 /Labamba Lambda-cyhalothrin + Canola, - Chlorantraniliprole mustard, 91 ml 225 ml 7 Voliam Xpress flax Chlorpyrifos1 Canola, Lorsban /Pyrinex flax 304-405 ml 750 ml – 1 L 21 17,20-22 /Nufos /Citadel /Warhawk

Restrictions - Decis, Matador: Apply when temperatures are below 25C.

WCCP Guide to Integrated Control of Insect Pests o f Crops

References - 1. Wise et al. 2009. Can. Entomol. 619-626. 2. Turnock and Bilodeau. 1985. Can. Entomol. 1065-1066. 3. Turnock. 1987. Can. Entomol. 167-178. 4. Bracken and Bucher. 1977. J. Econ. Entomol. 70:701-705. 5. Ulmer et al. 2001. Can. Entomol.133: 509-20. 6. Gavloski and Lamb. 2000. Env. Entomol. 1258-67. 7. Turnock and Bilodeau. 1984. Can. Entomol. 257-267. 8. Wylie and Bucher. 1977. Can. Entomol. 823-837. 9. Mason et al. 1998. Can. Entomol. 321-336. 10. Erlandson. 1990. Journal of Invertebrate Pathology. 47-56. 11. Derksen and Blouw, Pest. Res. Rep. 1980:121, 122, 123. 12. McVicar and MacKenzie, Pest. Res. Rep. 1980:124. 13. McVicar and Makowski, Pest. Res. Rep. 1980:125. 14. Wise and Kitson, Pest. Res. Rep. 1980:128. 15. Wise and McVicar, Pest. Res. Rep. 1980:129, 130. 16. Wise, McVicar and Kitson, Pest Res. Rep. 1980:131. 17. Putnam, Pest. Res. Rep. 1970:126. 18. McDonald et al., Pest. Res. Rep. 1971:177. 19. Peterson et al., Pest. Rep. Rep. 1971:143. 20. Lee et al. 1972. Can. Entomol. 104:1745. 21. Stewart, Pest. Res. Rep. 1972:166. 22. Harris and Turnbull. 1975. Can. Entomol. 107:865. 23. Bailey. 1976. The Canadian Entomologist. 108: 1339-1344. 24. Brugger et al. 2010. Pest Management Science. 66: 1075-1081.

Blister Beetles (Coleoptera: Meloidae)

The Nuttall blister beetle, Lytta nuttalli Say, a large purple and green blister beetle, may feed on canola, particularly near caragana, Caragana arborescens Lam, hedges (1). They are gregarious and may feed on leaves, stems and flower heads of canola.

Another species of blister beetle, Epicauta ferruginea (Say), may also feed on the blossoms of canola (1).

Chemical Control – There are no insecticides registered for blister beetles on oilseed crops in Canada.

References - 1. Burgess. 1983. The Canadian Entomologist. 115: 875-876.

Cabbage Seedpod Weevil Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae)

Cabbage seedpod weevil (canola and mustard)

Economic threshold - Control is required at densities of 3 to 4 adult weevils per one 180 sweep net sample (1). Apply by air or ground when crops are in 10 to 20% flowering stage to prevent egg-laying into newly formed pods (1,2). This is the stage when 70% of plants in the field have at least 3 to 10 open flowers.

Oilseed Crops

Cultural Control – Plant Resistance: Yellow mustard (Sinapis alba) is resistant to cabbage seedpod weevil; oriental and brown mustards (Brassica juncea) are susceptible to feeding by cabbage seedpod weevil (3).

Trap crops: If a trap crop of Brassica rapa is planted at the same time as the main crop of Brassica napus, the B. rapa should flower several days earlier and effectively concentrate the weevils, which can be sprayed with an insecticide if needed (4).

Chemical control – IPM status of insecticides – All the insecticides registered in Canada for cabbage seedpod weevil in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Insecticide Crop Rate Rate Preharvest (ml/acre) (ml/ha) Interval (days) References

Lambda-cyhalothrin Canola, 34 83 7 5 Matador /Silencer mustard /Labamba

Deltamethrin Canola, 7 5 Decis 5 EC mustard 80 200 Decis 100 EC 40 99 Poleci 162 400 Lambda-cyhalothrin + Canola, 91 225 7 - Chlorantraniliprole mustard Voliam Xpress

Restrictions - Spray late in the day to minimize harmful effects to bees and other beneficial insects. Do not make more than 1 application per year by air.

References - 1. Dosdall, 2000 AAFRD Tech. Rep. 98M301, 65 pp. 2. Dosdall et al. 2001. Alta. Agr. Agdex 622-21, 4 pp. 3. Cárcamo et al 2007. Can. Entomol. 139 : 658-669. 4. Cárcamo et al 2007, Crop Protection 26: 1325-1334 5. Cárcamo et al 2005, Can. Entomol. 137: 476-87

Canola Flower Midge Contarinia brassicola Sinclair (Diptera: Cecidomyiidae)

Canola flower midge (canola)

Canola flower midge (Contarinia brassicola), a new species of Contarinia that induces flower galls on 7

WCCP Guide to Integrated Control of Insect Pests o f Crops

canola, was described from Saskatchewan, Alberta, and Manitoba in 2019 (1). Galls produced by canola flower midge were previously attributed to the swede midge in Saskatchewan.

Chemical Control – There are no insecticides registered for canola flower midge in Canada.

References - 1. Mori et al. 2019. Can. Entomol. 00: 1-18. .

Clover Cutworm Discestra trifolii (Hufnagel) (Lepidoptera: Noctuidae)

Clover cutworm (canola, mustard, and flax)

Economic thresholds – None, but as a nominal threshold check threshold levels for bertha armyworm as a guideline to determine if control measures are needed in canola.

Chemical Control –

IPM status of insecticides – All the insecticides registered in Canada for clover cutworm in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids, and predaceous insects.

Insecticide Crop Rate Rate Preharvest (vol/acre) (vol/ha) Interval References (days) Deltamethrin Canola, 7 2-5 Decis 5 EC mustard, 40 - 60 ml 100-150 ml

Decis 100 EC flax 20-30 ml 49-74 ml 40 (Poleci in Poleci 81-121 ml 200-300 ml flax)

References - 1. Dixon, Pest. Res. Rep. 1971:176. 2. Catellier and Wise, Pest. Res. Rep. 1982:99. 3. Catellier and Wise, Pest. Res. Rep. 1982:100. 4. McDonald, Pest. Res. Rep. 1975:260. 5. McDonald, Pest. Res. Rep. 1979:354.

Cutworms (Lepidoptera: Noctuidae)

Redbacked cutworm (Euxoa ochrogaster) Dingy cutworm (Feltia jaculifera), Army cutworm (Euxoa auxiliaries) Pale Western cutworm (Agrotis orthogonia)

Economic threshold - Pale western or redbacked cutworm - Apply an insecticide if densities exceed 4-5 larvae/m² in flax (8) or 10/m² in sunflowers (9). No thresholds have been established in canola but threshold levels in

Oilseed Crops

flax can serve as a guideline. Army cutworm - No thresholds have been determined. Larval densities of less than one-half cutworm per square foot destroyed a mustard crop (10).

Cultural Control - To prevent egg laying by pale western cutworm adults in summerfallow fields, destroy all plant growth in July and allow soil surface to crust until September 15. In areas where redbacked adults are present, avoid weedy growth in August and weedy patches in crops. Spring cultivation: Studies and observations from Alberta show that pale western cutworm populations can be reduced by cultivating the soil and keeping it free of all plant growth for a 10-day period after the cutworms had hatched and before the crop was seeded (11). Seeding Date: Larvae of the army cutworm usually cease feeding by June 1, thus crop seeded in the last week of May or later will escape feeding and damage by the larvae (10).

Chemical Control – IPM status of insecticides – Chlorantraniliprole is not harmful to some beneficial insects, such as parasitic Hymenoptera (13). Seed treatments containing cyantraniliprole also preserve some beneficial insects. All the other insecticides registered for cutworms in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids, and predaceous insects.

IInsecticide Crop Rate Rate Preharvest (ml/acre) (ml/ha) Interval (days) References

Seed Treatments Cyantraniliprole Canola, Sold as a component of a seed treatment that Lumiderm1 mustard also includes either Prosper EverGol or Helix Fortenza1 Vibrance Foliar Sprays Chlorantraniliprole Canola, Coragen mustard, flax, 101 250 1 sunflowers, safflower Deltamethrin Canola, 6,7 Decis 5 EC mustard, flax 80 200 7 (Decis) Decis 100 EC 40 99 Poleci (flax only) 162 400 40 (Poleci) Lambda-cyhalothrin Canola, 34 83 7 - Matador/Labamba mustard, flax (canola & flax only) Permethrin Canola, flax, Pounce /Perm- UP/IPCO sunflowers 73-158 180-390 Treat up to 5- - Syncro leaf stage Ambush 57-121 140-300 Chlorpyrifos2 Canola, flax Lorsban 4EC /Pyrinex sunflowers 354-486 875-1200 21 1-5 /Nufos /Citadel 486 1200 42 (sunflowers)

WCCP Guide to Integrated Control of Insect Pests of Crops

/Warhawk (sunflowers) (sunflowers) 1Do not apply any subsequent applications of a group 28 insecticide (such as Coragen) for a minimum of 60 days after planting seed treated with Lumiderm or Fortenza.

2Registration of chlorpyrifos has been cancelled. Existing stocks in Canada are being phased-out. The last date of sale by retailers is December 10, 2022. All use of chlorpyrifos must cease by December 10, 2023.

It may take several days for optimum control using insecticides. Not all cutworms will surface to feed on any given night and come in contact with the insecticide on the soil and plants. One of the reasons is that during moulting periods (between larval stages) the cutworms are inactive (12).

Restrictions - Pounce, Decis: Do not apply at temperatures above 25C.

References - 1. McDonald, J. Econ. Entomol. 62:30, 1968;65:533, 1972. 2. Askew et al., Pest. Res. Rep. 1973:151. 3. McDonald, Pest. Res. Rep. 1974:251. 4. Askew et al., Pest Res. Rep. 1974:244. 5. Philip and Dolinski, Pest. Res. Rep.1977:215. 6. McVicar and Wise, Pest. Res. Rep. 1982:113. 7. Wise and Long, Pest. Res. Rep. 1985:95. 8. Ayre. 1990. Can. Entomol. 122: 21-28. 9. NDSU Extension Service #E-1143 10. Jacobsen, J. Econ. Entomol. 1962. 55: 408. 11. Salt and Seamans, 1945. Can. Entomol. 77: 150-155. 12. Byers et al. 1992. J. Econ. Entomol. 85: 1146-1149. 13. Brugger et al. 2010. Pest Management Science. 66: 1075-1081.

Diamondback Moth Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae)

Diamondback moth (canola and mustard)

Monitoring- Adults- Adult male moths can be monitored using pheromone-baited traps. These traps can determine the presence of adults, but moth numbers are not directly related to larval density (7). Traps baited with pheromone released from gray rubber septa capture more males than those baited with red rubber septa (8). However, the most attractive commercially available sex pheromone lures tested attracted fewer diamondback moth males than calling virgin female moths (9). Wind trajectories from potential source regions of diamondback moth can occasionally successfully predict movement of diamondback moth between regions (10). Used in conjunction with a network of pheromone-baited traps, wind trajectories may help provide alerts of early northward movement of diamondback moth.

Larvae- Larvae can be monitored by removing the plants in an area measuring 0.1 square metre area (about 1 foot square), beating them on a clean surface, and counting the number of larvae dislodged from the plants. This procedure should be repeated in at least five locations in the field.

Oilseed Crops

Sampling with a sweep-net can determine the presence of general abundance of diamondback moth in the field, but is currently not a useful means for making management decisions because no studies have been conducted to relate levels caught in a sweep net to levels per foot square or yield loss. High levels of diamondback moth caught in sweep sampling can, however, prompt producers to perform counts of larvae per unit area (11).

Economic Thresholds - Research does not exist to allow for economic thresholds for diamondback moth in canola and mustard to be established. Nominal thresholds have been suggested for canola if larvae exceed 100- 150/m² in immature to flowering plants and 200-300/m2 in plants with flowers and pods (2). A nominal threshold of 25-33% defoliation, with larvae still present on plants, can be applied for canola at seedling stage (5). Threshold at all crop stages may be lower for Polish type canolas than for Argentine type canolas (3) and higher for mustard (5).

Biological Control- Over a 10 year period (1961-70) in Saskatchewan, 35 to 81% of first generation larvae of the diamondback moth were parasitized by the ichneumonid Diadegma insularis and the braconid Microplitis plutellae, averaging 68% (6). Larvae of green lacewings have been observed feeding on early-instar larvae and cocoons containing prepupae of diamondback moth (14). Rainfall may be a major mortality factor of eggs and early instars of diamondback moth (12). The larvae are very susceptible to drowning, and may be washed or wriggle to leaf axils or the ground where they drown in accumulated water (12). In cabbage, increased rainfall droplet density and diameter resulted in increased larvae falling from plants (13). Mortality rates of up to 74% have been reported from intense rain (12).

Chemical Control – IPM status of insecticides – Chlorantraniliprole is not harmful to some beneficial insects, such as parasitic Hymenoptera (15). All the other insecticides registered for diamondback moth in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Rate Rate Preharvest Insecticide Crop (ml/acre) (ml/ha) Interval References (days) Chlorantraniliprole Canola, mustard Coragen 51 125 1 Deltamethrin Canola, mustard Decis 5 EC 40-60 100-150 7 4 Decis 100 EC 20-30 49-74 Poleci 81-121 200-300 Lamba-cyhalothrin Canola, mustard Matador /Silencer 34 83 7 /Labamba Lambda-cyhalothrin + Canola, mustard - Chlorantraniliprole 91 ml 225 7 Voliam Xpress

WCCP Guide to Integrated Control of Insect Pests of Crops

Malathion Canola (500 & Malathion 500 85E), mustard 220- 345 550-850 7 1 Malathion 85E (85E) 109-168 270-415 Chlorpyrifos1 Lorsban /Pyrinex Canola 405 - 607 1000– 21 /Nufos /Citadel 1,500 /Warhawk

Restrictions - deltamethrin: Do not apply at temperatures above 25C. malathion: Do not apply at air temperatures below 20C.

References - 1. Putnam, Pest. Res. Rep. 1962:126. 2. Putnam, unpublished, 1976. 3. Harris, Sask. Agric., Regina, Sask. 1990. 4. Wise and Leader, Res. Rep. 1985:84,85. 5. Gavloski and Lamb. 2000. Env. Entomol. 1258-67. 6. Putnam, 1973. Can. J. Plant Sci. 911-914. 7. Miluch et al. 2013. Crop Protection. 89-97. 8. Miluch et al. 2014. J. Econ. Entomol. 2067-2076. 9. Evenden and Gries. 2010. J. Econ. Entomol. 103:654-661. 10. Hopkinson and Soroka. 2010. Agricultural and Forest Meteorology. 150: 1-11. 11. Dosdall et al., 2011. Prairie Soils and Crops Journal. 4: 66-76. 12. Harcourt. 1963. Can. Entomol. Soc. Mem. 32: 55–66. 13. Kobori and Amano. 2003. Applied Entomology and Zoology. 38: 249-253. 14. Harcourt. 1960. The Canadian Entomologist. 92: 419-428. 15. Brugger et al. 2010. Pest Management Science. 66: 1075-1081.

Flax Bollworm Heliothis ononis (Denis & Schiffermüller) (Lepidoptera: Noctuidae)

Flax bollworm (flax)

Economic threshold – Research does not exist to allow for economic thresholds for flax bollworm to be established. Nominal thresholds have been suggested for flax if 3% or more of bolls are infested. Infestations on flax are generally very rare. Chemical Control - No insecticides presently are registered.

Flea Beetles: Crucifer flea beetle (Phyllotreta cruciferae (Goeze)) and Striped flea beetle (Phyllotreta striolata (F.)) (Coleoptera: Chrysomelidae)

Oilseed Crops

Flea beetles (canola and mustard)

Most Susceptible Crop Stages: Yield of canola was reduced most by flea beetles when plants were damaged from the seeding stage to when the second true leaf was expanded, 5 to 10 days after germination, but was not reduced when they were damaged after reaching the stages where the third and fourth true leaves were expanded, 20 days after germination (1). Flea beetle feeding on canola in late-summer is rarely an economic concern. Flea beetle feeding that occurs when seeds in lower pods of canola are at the green stage or beyond is unlikely to affect seed yields regardless of the infestation rate of flea beetles (2). Even when seeds are translucent to green, numbers higher than 100 flea beetles per plant, and for some cultivars higher than 350 per plant, may be necessary to cause significant yield reductions. Conditions favouring increased feeding: Flea beetles feed most actively on canola when the weather is sunny, warm, and dry; cool damp weather reduces the intensity of feeding and aids plant growth (3).

Cultural control- Tillage: Damage to canola is greater under conventional tillage than with zero tillage (4,5). Seeding rates and row spacing: In conventional tillage flea beetle damage to seedlings may be reduced by increasing seeding rates to 10 kg/ha and widening row spacings to 25 cm. (5). In zero tillage optimal seeding rates to reduce flea beetle damage are about 8 kg/ha.

Plant Resistance- Yellow mustard (Sinapis alba) seedlings are highly resistant to feeding by flea beetles, and Brassica juncea is partially resistant (6). Seedlings from large canola seeds were more tolerant to damage from flea beetles than seedlings from medium or small seeds for both Brassica rapa (18) and B. napus (7). This was because of a higher initial shoot biomass and higher growth rate when flea beetle damage was severe.

Chemical Control – IPM status of insecticides – The seed treatments registered for flea beetles will preserve some beneficial insects. All foliar insecticides registered for flea beetles in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Seed Treatments Insecticide Crop Rate References (vol/kg seed) Thiamethoxam Canola, mustard Helix Vibrance1 15 ml 8, 9, 10 Clothianidin Canola, mustard Prosper EverGol1 (Prosper EverGol); 9, 10 NipsIt INSIDE Canola (NipsIt) 250-666 ml / 100 kg seed (NipsIt)

WCCP Guide to Integrated Control of Insect Pests of Crops

Cyantraniliprole Canola, mustard 960 – 1600 ml / Lumiderm1,2 100 kg seed Fortenza1,2 (Lumiderm); 500 – 1,333 ml / 100 kg seed (Fortenza) Flupyradifurone Canola 625-1042 ml / Buteo Start 100 kg seed Imidacloprid Canola, mustard 0.67-1.33 L / 100 Sombrero kg seed 1For use by commercial seed treaters only. 2Do not apply any subsequent applications of a group 28 insecticide (such as Coragen) for a minimum of 60 days after planting seed treated with Lumiderm or Fortenza. Lumiderm is sold as a component of a seed treatment that also includes either Prosper EverGol or Helix Vibrance. Fortenza is sold as a component of a seed treatment that also includes Helix Vibrance.

Foliar Sprays

Rate Rate Preharvest Insecticide Crop (ml/acre) (ml/ha) Interval (days) References Deltamethrin Canola, mustard Decis 5 EC 40 – 60 100 – 150 7 12, 13 Decis 100 EC 20-30 49-74 Poleci 81-121 200-300 Lambda- cyhalothrin Canola, mustard Matador /Silencer 34 83 7 - /Labamba Cypermethrin Canola, mustard Mako (canola only) 20 50 30 14 UP-Cyde/Ship 56.6 140 Permethrin Canola Treat up to 5- 15 Pounce /Perm-Up 36 – 73 90 – 180 leaf stage /IPCO Syncro Ambush 28 - 57 70 - 140 Lambda-cyhalothrin + Canola, mustard 91 225 7 - Chlorantraniliprole Voliam Xpress Malathion Canola (500 and 450 1120 7 15, 16 Malathion 500 85E) 217-346 535-855 Malathion 85E Mustard (85E) Carbamates Canola 202 500 Seedling Sevin XLR application only

Restrictions - Matador: Apply only one application per year by air. Decis / Poleci: Do not apply at temperatures above 25C. Malathion: Do not apply at air temperatures below 20C.

Oilseed Crops

Notes - In greenhouse experiments, P. cruciferae had higher mortality and fed less when exposed to seed treatments with thiamethoxam and clothianidin than did P. striolata (9).

References - 1. Bracken and Bucher. 1986. The Canadian Entomologist. 118: 319-324. 2. Soroka and Grenkow. 2012. Can. J. Plant Sci. 92: 97-107. 3. Burgess. 1977. The Canadian Entomologist. 109: 21-32. 4. Milbraith et al. 1995. Can. Entomol. 127: 289-93. 5. Dosdall et al. 1999. Crop Protection 18: 217-224. 6. Brandt and Lamb. 1993. The Canadian Entomologist. 125: 1011-1021. 7. Elliott et al. 2008. Can. J. Plant Sci. 88: 207-217. 8. Antwi et al. 2007. J. Econ. Entomol. 100: 1201-1209. 9. Tansey et al. 2008. J. Econ. Entomol. 101 : 159-167. 10. Knodel et al. 2009. Arthropod Management Tests. 34: F10. 11. Wise, Pest. Man. Res. Rep. 1993:26, 1995:32. 12. Wise, Pest. Res. Rep. 1983: 95. 13. Elliott et al. 2007. Can. Entomol. 139: 534-544. 14. Romanow et al., Pest. Res. Rep. 1977:151; 1982:84; 1983:83. 15. Weiss et al. 1991. J. Econ. Entomol. 84: 1597-1603. 16. Askew et al., Pest Res. Rep. 1974:226,228; 1976:127,129,131; 1977:144. 17. Westdal et al., Pest. Res. Rep. 1976:134,136; 1980:115. 18. Elliott et al. 2007. Can. J. Plant Sci. 87: 385-393.

Grasshoppers (Orthoptera: Acrididae)

Cultural Control - · Fall stubble cultivation may reduce egg pod survival. · Destroying green growth on stubble in the spring at the time hatching may help to starve young grasshoppers. · Barrier strips of a non-preferred crop like oats next to an infested area at the margin of fields may delay young grasshoppers from feeding on susceptible crops (2). · Trap crops or weeds in an adjacent summerfallow field can attract grasshoppers where they can be controlled with an insecticide (3).

Chemical Control – IPM status of insecticides – Eco Bran Bait will preserve most beneficial insects (4). Chlorantraniliprole is not harmful to some beneficial insects, such as parasitic Hymenoptera (5). All other foliar insecticides registered for grasshoppers in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Trade Name Rate Rate Preharvest Crop (vol/acre) (vol/ha) Interval Reference (days) s Carbaryl Seedlings Eco Bran Bait Canola 0.8 – 1.6 kg 2 - 4 kg only -

WCCP Guide to Integrated Control of Insect Pests of Crops

Chlorantraniliprole Canola, 51 – 101 ml 125 – 250 ml 1 Coragen mustard, flax, sunflowers, safflower Deltamethrin Canola, Decis 5 EC mustard, 40-60 ml 100-150 ml 7 Decis 100 EC flax 20-30 ml 49-74 ml 40 (Poleci in Poleci 81-121 ml 200-300 ml flax) (ground), 121 (ground), 300 ml (air) ml (air) Lambda- cyhalothrin Canola, Matador /Silencer mustard, 25 - 34 ml 63-83 ml 7 - /Labamba (young flax (Ground) grasshoppers only) 34 ml (Air) Cypermethrin (young grasshoppers only) Canola 30 Mako 20 – 28 ml 50 – 70 ml UP-Cyde 33 – 46 ml 81 - 114 ml Lambda-cyhalothrin + Canola, 91 ml 225 ml 7 - Chlorantraniliprole mustard, Voliam Xpress flax, sunflowers, safflower Malathion Canola, Malathion 500 flax, 0.45-0.69 L 1.1-1.7 L 7 1 Malathion 85E mustard 0.217-0.346 L 0.535-0.855 L (85E only) Chlorpyrifos1 Lorsban 4E Canola 235-354 ml 580-875 ml 21 1 /Pyrinex /Nufos /Citadel /Warhawk Dimethoate Cygon /Lagon Canola, 340 - 364 ml 850-900 ml 21 - safflower 222 - 400 ml 550-990 ml

Restrictions - Do not apply when bees are present (with the exception of Eco Bran and chlorantraniliprole). Apply higher rates when foliage is dense or if grasshopper nymphs are past the third instar stage. Do not apply Malathion at air temperatures below 20C or Matador and Decis above 25C.

References - 1. Charnetski, Pest. Res. Rep. 1975: 210. 2. Olfert, Grasslands and Grassland Health, 2000: 61-70. 3. Olfert. 1986. Can. Entomol. 133-140.

Oilseed Crops

4. George et al. 1992. Environmental Entomology. 21: 1239-1247. 5. Brugger et al. 2010. Pest Management Science. 66: 1075-1081.

Lygus Bugs (Hemiptera: Miridae)

Lygus bugs (canola, mustard, flax, confectionary sunflowers)

Monitoring- Canola - Thresholds are based on the number of lygus bugs sampled per 10 sweeps with a 38 cm diameter sweep net (2). Canola should be sampled when flowering is complete and seeds are enlarging in the lower pods (stage 4.4), particularly if precipitation is low. If densities are near but less than the threshold at stage 4.4, canola should be resampled at stage 5.1 (when seeds in the lower pods are full size, translucent). If densities are sufficiently high, control is still warranted at stage 5.2 (seeds in lower pods green).

Lygus bug densities should be determined from a minimum of 15 samples of 10 sweeps or 10 samples of 20 sweeps per field (3). Samples can be collected from along the edge or at right angles from the edge of the field. Research has shown that samples taken along the edge of commercial fields and at various distances into the field all gave similar estimates of plant bug density (3). Sampling along the edge reduces effort during years when thick crop growth impedes access to the field. For edge sampling, the area selected for sampling should be at a crop stage similar to that in the main part of the field.

When precipitation is greater than 100 mm from the onset of bud formation to the end of flowering in canola, the plant may partially compensate for damage by lygus bugs (2).

Economic thresholds -

Canola – A threshold of 20-30 per 10 sweeps is suitable for good growing conditions. Using the lower end of the threshold (about 20 per 10 sweeps) may be appropriate for stressed canola with less ability to compensate for feeding.

Pods are the focus for crop protection efforts against lygus in canola. The most vulnerable crop stage for lygus feeding is after flowering and when seeds are enlarging on lower pods. When most pods become “leathery” and when seeds inside are firm, lygus bugs can no longer penetrate the pods or seeds with their mouthparts and are no longer an economic threat.

Confectionary sunflowers – Research in North Dakota found that feeding by adult lygus bugs resulted in 32.7 damaged seeds per head (4). Approximately 5% of seeds in a head were damaged per adult. Damage to sunflower heads was approximately twice as severe when infestations occurred at growth stages R4 and R5 compared with stages R6 and R7. One adult lygus bug per 9 heads can result in economic loss through the reduction of seed quality. Lygus bug management should be initiated between the R4 to R5.1 stage if adult densities reach the economic injury level (4). Note: Because the most appropriate timing of insecticides to control Lygus bugs in sunflowers includes flowering stages, steps to minimize harm to pollinators should be taken and insecticides should only be used when economic thresholds are exceeded. 17

WCCP Guide to Integrated Control of Insect Pests of Crops

Oilseed Sunflowers - No control is needed in oilseed sunflowers not used for human consumption.

Flax: Although Lygus bugs can occasionally reach high densities in flax, flax is tolerant of their feeding damage under good growing conditions. A study in Manitoba found that under good growing conditions, populations of up to 100 per 10 sweeps did not reduce yield (5).

Chemical Control – IPM status of insecticides – All the insecticides registered and sold in Canada for Lygus bugs in oilseed crops are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Insecticide Crop Rate Rate Preharvest References (ml/acre) (ml/ha) Interval (days) Deltamethrin Canola, 7 1 Decis 5 EC mustard, flax 60 150 Decis 100 EC 30 74 Poleci (canola and 121 300 mustard only) Lambda- cyhalothrin Canola, 34 83 7 - sunflowers Matador / Silencer (canola only) / Labamba Lambda- Canola, 91 225 7 - cyhalothrin + mustard, flax, Chlorantraniliprole sunflowers Voliam Xpress Chlorpyrifos1 Canola 1 Lorsban /Citadel 200-400 500-1000 21 /Pyrinex /Nufos /Warhawk

References - 1. Wise, Pest. Res. Rep. 1988: 65, 66. 2. Wise and Lamb. 1998. Can. Entomol. 130: 825-36. 3. Wise and Lamb. 1998. Can. Entomol. 130: 837-51. 4. Charlet. 2003. Helia. 26: 83-92. 5. Wise and Lamb. 2000. Can. Entomol. 132: 369-371.

Painted Lady Butterfly Vanessa cardui (L.) (Lepidoptera: Nymphalidae)

Oilseed Crops

Painted lady butterfly (sunflowers, canola, mustard)

Larvae (sometimes referred to as thistle caterpillars) feed chiefly on Canada thistle (Cirsium arvense (L.)) in the Canadian portion of their range, and are thus beneficial in this regard (1,2). Occasionally, when large migrations occur, larvae may feed on sunflowers (1), canola and mustard (2), and borage (3). Contamination of canola and mustard seed by frass of thistle caterpillars has occurred (2) but is likely to be an infrequent occurrence as it is only a potential problem in years when thistle caterpillar is abundant and when the larvae have not matured well in advance of harvest.

Biological Control – Usually heavily parasitized, and is also subject to bacterial disease (1).

References - 1. Westdal, 1975. Insect Pests of Sunflowers. In, Oilseed and Pulse Crops in Western Canada. pp.475-495. 2. Byers et al., 1984. Can. Entomol. 116: 1431-1432. 3. Miranpuri et al., 1993. J. of Applied Entomology. 116: 156-162.

Red Turnip Beetle Entomoscelis americana Brown (Coleoptera: Chrysomelidae)

Red turnip beetle (canola, mustard)

Cultural Control - The eggs are layed on the soil late in the summer beneath canola or related plants. They hatch in the spring and the larvae feed on volunteer canola or winter annual weeds such as flixweed and mustards. Destruction of these food plants while they are still in the early larval stages may starve larvae. Adults are very mobile and will migrate to canola in summer to feed.

Chemical Control – No insecticides are registered for use on red turnip beetles.

Root Maggots Delia spp. (Diptera: Anthomyiidae)

Root Maggots (canola) A complex of 5 root maggot species in the genus Delia occur in canola field in Western Canada: D. floralis (the turnip maggot), D. radicum (the cabbage maggot), D. platura (seed corn maggot), D. florilega (bean seed maggot), and D. planipalpis.

Cultural Control –

Variety selection: Comparisons on the level of susceptibility of cultivars of canola and mustard to root maggots demonstrated that varieties of Polish canola (B. rapa) were most susceptible, Brassica napus (Argentine canola) and B. juncea were intermediate in susceptibility, and yellow mustard (S. alba) was least susceptible (1,2). S. alba has both antibiotic and antixenotic effects on root maggots (7).

Cultivation: Cultivating prior to seeding reduces adult emergence from overwintered pupae (3). Root maggot infestations are greater under zero-till systems than under conventional tillage, but yields 19

WCCP Guide to Integrated Control of Insect Pests of Crops under zero tillage usually still exceed those with conventional tillage (5).

Seeding Rate and Row Spacing: Seeding at approximately twice the recommended rate (10 kg/ha) (4), and at a row spacing of 20 or 30 cm (5) reduces damage from root maggots and results in improved yields.

Biological Control – The rove beetle Aleochara bilineata is a predator of root maggot eggs and larvae, and larvae of A. bilineata are parasites of root maggot pupae (6). A single adult of A. bilineata is capable of consuming an average of 23.8 eggs or 2.6 larvae per day (6).

Chemical Control - No insecticides are registered for control of roots maggots in canola.

References - 1.Griffiths, Proc. GCIRC Congress, 1991:528-535. 2. Dosdall et al. 1994. Can. Ent. 126: 251-260. 3. Dosdall et al. 1996. Can. Ent. 128:1157-1165. 4. Dosdall et al., Can. J. Plant Sci. 76: 169-177. 5. Dosdall and Dolinski. AARI Tech. Rep. 95M723, 1997: 40pp. 6. Read, D.C. 1962. Can. Ent. 94: 417-424. 7. Jyoti et al. 2001. J. Econ. Entomol. 94: 942-949.

Sunflower Beetle Zygogramma exclamationis (F.) (Coleoptera: Chrysomelidae)

Sunflower beetle (sunflowers)

Economic Thresholds - Control is required in sunflowers with 1 - 2 adults/seedling or 10 - 15 larvae/plant (1). Count larvae in the plant tops where they rest during the day. Sample a minimum of 20 plants to estimate larval densities.

Cultural Control – Planting date: Research in North Dakota found that sunflower beetle adult and larval populations decreased as planting date was delayed (2). Delaying planting did not reduce the effectiveness of the parasitic fly Myiopharus macellus which attacks the sunflower beetle larvae.

Biological Control- The tachinid fly Myiopharus macellus is an important natural enemy of sunflower beetle larvae (3).

Chemical Control – IPM status of insecticides – The seed treatment registered for sunflower beetles will preserve most beneficial insects. All foliar insecticides registered for sunflower beetles are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Rate Rate Preharvest Insecticide (ml/acre) (ml/ha) Interval (days) References Thiamethoxam A seed treatment. Cruiser Maxx Sunflower seeds can not be treated with Cruiser

Oilseed Crops

Sunflowers Maxx Sunflowers in Canada. Deltamethrin Decis 5 EC 40 100 70 4, 5 Decis 100 EC 20 49 Poleci 81 200 Lambda-cyhalothrin Matador / Silencer / 17 – 25 (ground) 42 - 63 7 - Labamba 34 (air) 83 Cypermethrin Mako 28 70 70 5, 6 UP-Cyde/Ship 40 100 Lambda-cyhalothrin + Chlorantraniliprole 91 ml 225 ml 7 - Voliam Xpress

Restrictions - cyhalothrin-lambda: Only one application by air per year. cypermethrin: Avoid application at temperatures above 27C. Only one application by air. deltamethrin: Do not apply at temperatures above 25C.

References - 1. Deedat, Ph.D. Thesis, Univ. of Manitoba. 1987:92. 2. Charlet and Knodel. 2003. J. Econ. Entomol. 96: 706-713. 3. Charlet. 1992. J. Econ. Entomol. 85: 766-771. 4. Westdal et al., Pest. Res. Rep. 1980:130. 5. Romanow and Askew, Pest. Res. Rep. 1983:144. 6. Emilson, Pest. Res. Rep. 1983:141,142,143; 1984:160,161,162,163.

Sunflower Bud Moth Suleima helianthana (Riley) (Lepidoptera: Tortricidae)

Sunflower bud moth (sunflowers)

Larvae feed in the pith area of either the stalk or receptacle (head). Larvae can cause seed loss when they occur in either the terminal of small plants or in small heads (1). Larvae keep the burrow open and continually push frass its entrance. As larvae grow, frass accumulates at the entrance of the burrow.

Cultural Control – Research in North Dakota found that late planting dates (early to mid-June) of sunflowers reduced the percentage of heads damaged by sunflower bud moth compared with early planting dates (2).

Reference - 1. Rogers. 1979. Environmental Entomology. 8: 113-116. 2. Knodel et al. 2011. J. Econ. Entomol. 104: 1236-1244.

WCCP Guide to Integrated Control of Insect Pests of Crops

Sunflower Maggots (Diptera: Tephritidae)

Sunflower maggot – Strauzia longipennis (Wied) Neotephritis finalis (Loew) Gymnocarena diffusa Snow Sunflower maggots - 3 species (Strauzia longipennis, Gymnocarena diffusa, Neotephritis finalis) feed on sunflowers Larvae of Strauzia longipennis tunnel in the pith of sunflower stalks. Depending on the number of maggots, tunnelling may vary from one short tunnel to complete destruction of the pith (1). The plants can remain healthy and vigorous in appearance even when there is complete pith destruction (1).

Larvae of Neotephritis finalis feed on developing seeds of sunflowers (2).

Larvae of Gymnocarena diffusa inhabit and feed on the spongy tissue of the sunflower receptacle (3).

Cultural Control – Planting date: Research in North Dakota found that late planting dates (early to mid-June) reduced damage from Neotephritis finalis compared with early planting dates (mid- to late May) (4).

Chemical Control – Insecticides are not registered for sunflower maggots in Canada.

References – 1. Westdal and Barrett. 1960. Can. Ent. 481-488. 2. Arthur and Mason. 1989. Can. Ent. 729-735. 3. Kamali and Schulz. Annals of the Ent. Soc. America. 1973: 288-291. 4. Knodel et al. 2011. J. Econ. Entomol. 104: 1236-1244.

Sunflower Midge Contarinia schulzi Gagné (Diptera: Cecidomyiidae)

Sunflower Midge (Sunflowers)

Economic Threshold - Destruction of seeds and distortion of heads can cause serious losses in fields in the Red River Valley of Manitoba. Losses are more severe around field edges. Losses can be estimated by sampling heads and classifying them by the degree of head cupping and the relative area of seed destroyed (1).

Cultural Control - Some cultivars show some resistance to feeding by sunflower midge (2,3).

Chemical Control - No chemical control is feasible because the larvae feed within the head.

Reference - 5. Bracken. 1991. Can. J. Plant Sci. 71: 81-85. 6. Anderson and Brewer. 1991. J. Econ. Entomol. 84: 1060-1067. 7. North Dakota Field Crop Insect Management Guide – 2009. http://www.ag.ndsu.edu/pubs/plantsci/pests/e1143w1.htm

Oilseed Crops

Sunflower Moths

Banded sunflower moth - Cochylis hospes Walsingham (Lepidoptera: Tortricidae) on sunflowers Sunflower moth - Homoeosoma electellum Hulst (Lepidoptera: Pyralidae) on sunflowers.

Monitoring - Pheromone traps can be used to determine when adults of the banded sunflower moth and sunflower moth are present (3). Methods of determining the economic injury level of the banded sunflower moth based on sampling adult (4) and eggs (5) have been developed. Egg sampling is best done using a head-mounted 3.5X magnifier (available from most IPM suppliers) to leave both hands free for manipulating the buds being observed. To sample eggs, divide each side of the field into 2 sections; sample the centre of each section at 20 feet into the field from the field edge; randomly select 5 buds, and for each bud randomly select 6 bracts form the outer whorl and count the eggs on each bract.

Economic threshold: Sunflower moth - For field scouting, 1 to 2 moths per 5 plants is necessary for treatment. For pheromone traps, an average of 4 moths per trap per day has been suggested as needed for an insecticide application (1). Banded Sunflower moth – Formulas for economic injury levels for both the egg sampling and adult moth sampling techniques are available, see: http://library.ndsu.edu/tools/dspace/load/?file=/repository/bitstream/handle/10365/4798/e823.pdf?sequen ce=1 Because banded sunflower moth levels are often higher on field margins, if the average egg count equals of exceeds the economic threshold, a second calculation for economic distance determines the extent of the economic injury level into the field.

Cultural Control – Research in North Dakota has shown that delaying the planting of sunflowers until late May or early June can reduce levels of damage by banded sunflower moth (2).

Biological Control – Research in North Dakota found that honey bees, Apis mellifera L., can vector Bacillus thuringiensis variety kurstaki from hives equipped with a pathogen applicator to sunflower heads and the amount of B. thuringiensis deposited on the head is sufficient to result in high mortality of larvae of the banded sunflower moth (7).

Chemical Control - Do not apply an insecticide if insects are not found within 2 weeks of flowering. Apply when 20-50% of the heads are in bloom.

IPM status of insecticides – Bacillus thuringiensis kurstaki is specific in killing larvae of Lepidoptera, and will not harm populations of beneficial insects. Chlorantraniliprole is not harmful to some beneficial insects, such as parasitic Hymenoptera (6).

Insecticide Crop Rate Rate Preharvest (g/acre) (g/ha) Interval References (days) Bacillus thuringiensis kurstaki Dipel 2X DF (sunflower moth) Sunflowers 127 - 253 315-625 N/A - 23

WCCP Guide to Integrated Control of Insect Pests of Crops

Bioprotec CAF (sunflower moth) 320-650 ml 790-1600 ml 0 Chlorantraniliprole Coragen (reduces damage by Sunflowers 101 - 152 250 - 375 1 banded sunflower moth)

References - 1. NDSU Extension Service, Pub. # E-1143. 2. Oseto et al. 1989. J. Econ. Entomol. 82: 910-912. 3. Underhill et al. 1986. Environ. Entomol. 15: 1063-1066. 4. Charlet and Barker. 1995. Helia. 18: 59-66. 5. Mundal and Brewer. 2008. J. Econ. Entomol. 101: 969-975. 6. Brugger et al. 2010. Pest Management Science. 66: 1075-1081. 7. Jyoti and Brewer. 1999. Environmental Entomology. 28: 1172-1176.

Sunflower Seed Weevils (Coleoptera: Curculionidae)

Red sunflower seed weevil - Smicronyx fulvus LeConte, and Gray sunflower seed weevil - Smicronyx sordidus LeConte

Monitoring - Count the number of weevils found on a minimum of 25 plants when the yellow ray petals are beginning to show (2).

Economic Threshold - One to two adults/head in confectionery sunflower and 12-14 adults/head in oilseed sunflowers for plant densities of 45 000 - 55 000/ha (1).

Cultural Controls- Research in North Dakota showed that planting sunflowers in early to mid May will help reduce damage by red sunflower seed weevil (3). However, early planting may increase the risk of damage by other insects on sunflowers.

Chemical Control – Optimal Spray Timing: Early anthesis, when 30 - 70% of sunflower heads are in early pollen formation, i.e. R-5.1 stage (for example, when 3 - 7/10 plants show ray petals and at least one row of disc flowers). Reinfestation of the field may occur in areas with a high weevil population. Fields at 70% pollen shed stage are no longer susceptible to economic damage (2).

IPM status of insecticides – All insecticides registered for sunflower seed weevils are more general in their impact on insect communities, also being harmful to pollinators, parasitoids and predaceous insects.

Because the most appropriate timing of insecticides to control sunflower seed weevils is during the flowering stage, steps to minimize harm to pollinators should be taken and insecticides should only be used when economic thresholds are exceeded.

Rate Rate Preharvest Insecticide (ml/acre) (ml/ha) Interval (days) References Cypermethrin

Oilseed Crops

Mako 28 70 UP-Cyde/Ship 40 100 70 - Chlorpyrifos1 Lorsban /Pyrinex 485 1200 42 - /Nufos /Citadel

Reference - 1. Peng and Brewer. 1995. Can. Entomol. 127: 561-568. 2. N. Dakota State Univ. Coop. Ext. Serv. Publ. #E-817. 3. Oseto et al. 1987. J. Econ. Entomol. 80 : 190-192.

Zebra Caterpillar Melanchra picta (Harris) (Lepidoptera: Noctuidae)

Larvae of zebra caterpillar will feed on many crop and non-crop plants including canola and flax.

Biological Control- A study of zebra caterpillar collected from blueberries in British Columbia found that 50% were parasitized by the braconid wasp Microplitis mamestrae (1).

References - 1. Li et al. 1993. Can. Entomol. 125: 405-406.